An Identicon is a visual representation of a hash value. Small unique icons that contain patterns are easy to remember. Furthermore those can be utilised by human brain to recognize objects faster compared to text information.

public BitmapSource GenerateIdenticon(Object value)
{
	int width = 9;
	int height = width;
	int stride = (PixelFormats.Indexed8.BitsPerPixel * width) / 8;
	byte[] pixels = new byte[height * stride];
	int hash = value.GetHashCode();
 
	BitmapPalette myPalette = new BitmapPalette(new Color[] { Colors.White, Colors.LightGray, Colors.LightSeaGreen, Colors.White });
 
	for (int y = 0; y < 5; ++y)
	 for (int x = y; x < 5; ++x)
	 {
	 	byte color = (byte)(hash & 0x03);
		hash >>= 2;
 
		// II quadrant
		pixels[x + (y * stride)] = color;
		pixels[y + (x * stride)] = color;
 
		// I quadrant
		pixels[(8 - x) + (y * stride)] = color;
		pixels[(8 - y) + (x * stride)] = color;
 
		// III quadrant
		pixels[x + ((8 - y) * stride)] = color;
		pixels[y + ((8 - x) * stride)] = color;
 
		// IV quadrant
		pixels[(8 - x) + ((8 - y) * stride)] = color;
		pixels[(8 - y) + ((8 - x) * stride)] = color;
	 }
 
	return BitmapSource.Create(width, height, 96, 96, PixelFormats.Indexed8, myPalette, pixels, stride);
}